1. Field of the Invention
The present invention relates generally to a camera which is capable of switching a picture size, and more particularly to a camera which is capable of switching the picture size between a normal size and a size which is larger than the normal size in a film feed direction, and which varies the film feed amount in accordance with the picture size.
2. Description of Related Art
A camera, which is capable of switching the picture size between the normal size and the panoramic size within a film, has recently been put into practical use. On a 35 mm film, the upper and lower sections of the frame in the normal size are shielded properly, and the photograph is enlarged to be in a panoramic size (Japanese Patent Provisional Publication No. 5-72655). The quality of such a panoramic photograph is deteriorated because the enlargement scale is larger than in the normal size.
On the other hand, there is proposed a camera which extends the longer side of a frame in the normal size on the film so that the frame can be, for example, 24 mm.times.65 mm in the panoramic size (Japanese Patent Provisional Publication No. 8-106123).
The above-mentioned cameras must have a structure wherein the size of an aperture provided behind a taking lens is equal to that of a frame in the panoramic size, and the right and left sections of the aperture are shielded properly to perform the photography in the normal size.
In this case, the size of the opening in the aperture arranged behind the taking lens is equal to that of the frame in the panoramic size, and there are provided light shielding plates at the right and left sections of the aperture to switch the picture size. The light shielding plates slide within a plane parallel to an opening plane of the aperture.
The above-mentioned mechanism has a disadvantage because it requires a space into which the light shielding plate moves from the opening, and thus, the camera must be wide.
The conventional camera which is capable of switching the picture size between the normal size and the panoramic size, has a problem in that the film position must be corrected when the picture size is switched after the film is set by automatic one-frame winding, because the film feed amount varies according to the picture size.
According to the Japanese Patent Provisional Publication No. 8-106123, when the picture size is switched to the panoramic size while the photography in the normal size is waited, the film is further fed and stopped at a position for the panoramic size. On the other hand, when the picture size is switched to the normal size while the photography in the panoramic size is waited, the film is rewound and stopped at a position for the normal size. In this method, the film is positioned both in the film feed direction and in the film rewind direction, and therefore, the film cannot be positioned accurately due to the effects of a transport error resulting from the backlash of a film driving force transmission mechanism and an error in detection of perforations, etc.
Moreover, the conventional camera which is capable of switching the picture between the normal size and the panoramic size has a problem in that the number of residual frames differs according to the selected picture size because the film feed amount varies according to the picture size. Japanese Patent Provisional Publication No. 5-127213 discloses a camera which switches the display of the number of residual frames in response to the switching of the picture size, but it fails to disclose a process for the last frame.